Method of inhibiting the alkaline corrosion of tin containers



Patented Apr. 4, 1939 PATENT OFFICE METHOD OF INHIBITING THE ALKALINE CORROSION OF TIN CONTAINERS Anthony C. Nittl, Brooklyn, N. Y., assignor to E.

R. Squibb & Sons, New York, N. Y., a corporation oi New York No Drawing.

Application December 9, 1936,

Serial No. 114,951

8 Claims.

This invention relates to alkaline preparations packed in tin containers, which term is used herein to embrace containers made of, or internally coated with, tin or alloys of tin, especially tincoated iron cans, tin-coated lead collapsible tubes,

and tin collapsible tubes.

When alkaline preparations are packed in tin containers, there occurs an interaction (increasing with lapse of time and elevation of temperal0 ture) which tends to bring about corrosion of the tin container and alteration of the alkaline preparationa conspicuous instance of this alteration being the fading of phthalein dyes present in the alkaline preparation as coloring.

25 To avert such interaction, certain chemical agents and mechanical expedients (including linings of wax, rubber, and other inert materials) have been employed heretofore, but they either did not achieve the desired result or else introduced troublesome contaminating substances or entailed undue difiiculty or expense.

It is an object of this invention to provide a simple and efficient. method of minimizing such interaction; and it is a further object to provide a package comprising a tin container having therein an alkaline preparation so constituted as practically to eliminate the likelihood of such corrosion or alteration.

In the practice of this invention, there is incorporated into alkaline preparations to be packed in tin containers a compound having the general formula wherein X represents halogen, Y represents one of the group hydrogen and halogen, and Z represents one of the group hydrogen, halogen, and

4 methyl; preferably a compound selected from the class consisting of methyl iodide and compounds having the general formula A small proportion of these compounds suffices to eliminate the likelihood of, or at least to post pone for a very long period of time, appreciable interaction between alkaline preparations and tin containers in which they are packed. Where 5 the compound used has a comparatively high vapor pressure, the tin container should of course be vapor-tight.

Among the preparations to which the invention is applicable are foods, medicines, pharmaceuti- '10 cals, and cosmetics; particularly dentifrices. shaving cream, and substances like milk of magnesia.

Example 1 4 g., 8 g., or 16 g. of chloroform or 7.5 g. of carbon tetrachloride or of methylene dichloride is incorporated into a dentifrice consisting of 5 kg. of a suspension of magnesium hydroxide in glycerine, 5.2 kg. of glycerine solidified by means of about 3% of sodium stearate, 5.2 kg. of precipitated chalk, 100 cc. of flavoring, and other suitable ingredients, and colored pink by means of about 0.003% of erythrosin (sodium tetraiodo fluorescein); and when admixture is completed, 25 the smooth paste is packed in the familiar collapsible tin tubes. In a package so constituted. the erythrosin does not fade, the preparation does not undergo appreciable alteration on account of the tin container, and the tube does not suffer corrosion.

Example 2 20 g. of chloroform, of carbon tetrachloride, or of iodoform is incorporated into a shaving cream consisting of 4.8 kg. of superfatted soap, 385 g. 35 of glycerine, 200 g. of lanolin, coloring, odorous, and other suitable ingredients, and water to make 10 kg.; and when admixture is complete, the smooth mass is packed in the familiar collapsible tin tubes. Neither corrosion of the tube nor al- 0 teration of the contents because of the presence of the tin, takes place in the average, or even in a prolonged, interval between packaging and consumption.

It is to be understood that the foregoing ex- 45 amples are merely illustrative and not limitative of the invention, which may be variously otherwise embodied-as with respect to the specific alkaline preparations packed in tin containers, the compounds used and their proportions, and the procedures followed-within the scope of the appended claims.

I claim:

1. The method of minimizing interaction between 9. tin container and an alkaline preparau 'tion to be packed therein that comprises incorporating into the latter a compound having the general formula wherein X represents halogen, Y represents one .of the group hydrogen and halogen, and Z repre- 10 sents one of the group hydrogen, halogen, and

methyl, in amount sufiicient to inhibit the alkaline corrosion of the tin container.

2. A package comprising a tin container having therein an alkaline preparation into which 15 there has been incorporated a compound having the general formula wherein X represents halogen, Y represents one of the group hydrogen and halogen, and Z represents one of the group hydrogen, halogen, and

methyl in amount suiiicient to inhibit the alka line corrosion of the tin container.

4. A package comprisng a tin container having 40 therein an alkaline preparation into which chloreform has been incorporated, in amount sufilcient to inhibit the alkaline corrosion of the tin container.

5. A package comprisng a tin container having therein an alkaline preparation into which carbon tetrachloride has been incorporated, in amount suflicient to inhibit the alkaline corrosion of the tin container.

6. A package comprising a tin container having therein an alkaline preparation into which iodoform has been incorporated, in amount sufficient to inhibit the alkaline corrosion of the tin container.

7. A package comprising a tin tube having therein an alkaline dentifrice into which there has been incorporated a compound having the general formula wherein X represents halogen, Y represents one of the group hydrogen and halogen, and Z represents one of the group hydrogen, halogen, and methyl, in amount sufiicient to inhibit the alkaline corrosion of the tin tube.

8. A package comprising a tin tube having therein an alkaline shaving cream into which there has been incorporated a compound having the general formula wherein X represents halogen, Y represents one of the group hydrogen and halogen, and Z represents one of the group hydrogen, halogen, and methyl, in amount suflicient to inhibit the alkaline corrosion of the tin tube.

ANTHONY C. NITTI. 

